Drive mechanism for flying shears and the like



April 10, 1962 E. w. NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE 8 Sheets-Sheet 1 OriginalFiled Nov. 5, 1953 April 10, 1962 E. w. NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE Original Filed Nov. 5,1953 8 Sheets-Sheet 2 April 10, 1962 E. w. NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE Original Filed Nov. 5,1953 8 Sheets-Sheet 3 Apnl 10, 1962 E. w. NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE Original Filed Nov. 5,1953 I a Sheets-Sheet 4 CONSTANT SPEED l 2.0 30 4O 5O 6O 7O 8O 90 I00 "0I I I I I I I CRANK ROTATION DEGREES April 10, 1962 E. w. NILSSON3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE Original Filed Nov. 5,1953 8 Sheets-Sheet 5 April 10, 1962 E. w. NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE 8 Sheets-Sheet 6 OriginalFiled Nov. 5, 1953 al mn DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKEOriginal Filed. Nov. 5, 1953 8 Sheets-Sheet '7 April 10, 1962 E. w.NILSSON 3,028,779

DRIVE MECHANISM FOR FLYING SHEARS AND THE LIKE Original Filed. Nov. 5,1953 8 Sheets-Sheet 8 United States Patent The present application is adivisional application of my co-pending patent application, Serial No.390,288, filed November 5, 1953, and which has since matured into UnitedStates Patent No. 2,829,713.

The present invention relates to driving mechanisms and particularly toan improved driving mechanism which is particularly adapted foroperation with shearing apparatus of the type hereinafter disclosed. Itshould be understood at the outset, however, that although the drivingmechanism is shown and described in conjunction with a particularshearing device that it may be used to drive other types of equipment aswill be apparent to those skilled in the arts.

In the severing of continuously moving materials such as metal sheet andstrip, for example, it is common practice to synchronize the speed ofthe cutting device as closely as possible with that of the movingmaterial. In this manner the cutting operation may take place withoutsubstantial longitudinal movement between the cutting device and thematerial being cut. But it is further true that prior to the presentinvention it has not been possible, without extremely complicated andcostly mechanisms, to synchronize the cutting device and material forlonger than a relatively short instant. Thus, it has heretofore beennecessary to effect a complete severing operation in a very short time,resultingin the application of high shock loads and forces to thecutting apparatus, and thereby complicating the construction andmaintenance of such apparatus.

It is therefore an object of the present invention to provide a drivingmeans which drives a cutting device in substantially exact synchronismwith the moving material to thereby provide for a substantial period oftime wherein the material may be severed in an accurate and even manner.Thus, the material can be severed without heavy shock forces and withoutequipment of a particularly heavy or rugged nature.

Yet another and important object of the invention is the provision of animproved driving mechanism which is particularly adapted for theoperation of the shearing apparatus of the type disclosed, whereby theshearing cycle of the apparatus may be readily varied in relation to therate at which material continuously moves through the shearingapparatus.

Thus, in order to alter the length of material to be severed it maybenecessary to either increase or decrease the number of shearing cyclesper unit of material travel. Heretofore it has been suggested for suchpurpose to employ a differential drive mechanism, monitored by means ofa variable speed mechanism having positive drive characteristics,whereby a rugged high power drive is atforded which is infinitelyvariable within predetermined design limits. The ditferential mechanismin this type of drive arrangement is employed to overcome the inherentinability of positive drive variable speed devices of reasonablephysical size to deliver high power output. In the present inventionthere are employed, in combination, a differential andpositive-infinitely-variable, or -P.I.V. drive, these mechanisms,however, being arranged in an improved relation whereby more efficientand more desirable power transmission is obtained. Particularly, thepresent invention provides a novel power transmission device of theabove described type wherein ice the variable drive or P.I.V. unit isarranged to be operated at a constant input speed notwithstandingintentional wide variations in the speed of the driving motor.

To fully comprehend the above object it must be understood that shearapparatus of the type herein contemplated includes not only a shearingdevice but feeding rolls or mechanism for feeding the material to theshearing device, the feeding and shearing devices being maintained inpredetermined correlation by means of a drive mechanism of the abovetype whereby one of the devices may be varied in relation to the other.Now, inasmuch as there are necessarily certain shock forces inconnection with the operation of the shear device proper it has beendetermined to be more desirable to drive the shearing blades or devicethrough a direct gear drive from the main power source and independentlyof the more delicate P.I.V. mechanism, the latter being employed in thematerial feeding system which is substantially free of shock loads.Thus, to reduce or increase the number of shearing cycles per unit oftime it is necessary to slow down or speed up the main drive motor, asthe case may be. In turn, it is then necessary to speed up or slow downthe feed rolls in relation to the drive motor so that a constant linespeed may be maintained. And in the present invention I accomplish allthis while maintaining a constant input speed on the P.I.V. unit, aswill presently be explained in greater detail.

Another object of the invention is the provision of a flying shear ofthe rocking frame type, having separate drive connections for rockingthe frame and actuating the shearing devices, which is characterized bythe provision of an improved driving arrangement for driving theshearing devices and frame in equal cyclic periods while providingnon-uniformity in the instantaneous movement of both so that themovement of the frame is decelerated from its normal cyclic movementduring a severing operation while the cutting or shearing devices areaccelerated during this same period. And, as will become increasinglyapparent, the invention accomplishes this without unusual andcomplicated mechanisms, as has been heretofore required.

The above and other objects and advantages of the invention will becomeapparent upon full consideration of the following detailed specificationand accompanying drawings wherein is shown a preferred embodiment of myinvention.

In the drawing:

FIGURE 1 is a side elevation of a flying shear device constructed inaccordance with the teachings of my invention;

FIGURE 2 is an end elevation of the flying shear apparatus of FIGURE 1,showing, in partcular, the feed rolls and related mechanism;

FIGURE 3 is a top plan view of the complete flying shear system of myinvention, including the drive mechanism therefor; 7

FIGURE 4 is a longitudinal section view of my apparatus, taken generallyalong line IVIV of FIG- URE 3;

FIGURE 5 is an end elevation, partly in section of the shearing deviceforming a part of the apparatus of FIGURE 1;

FIGURE 6 is a section view of the drive mechanism which forms a part ofthe present invention, illustrating details of the construction andoperation of the drive;

FIGURES 7-9 are sequential views of the flying shear device of myinvention during various stages of a severing operation;

FIGURES l0-l2 are sequential views of the flying shear device of myinvention during return movement of the shear following a shearingoperation;

FIGURE 13 is an illustrative graph indicating the resultant velocity ofthe shearing blades of my improved shear device over approximatelyone-half of a complete shearing cycle; and

FIGURES l4 and 15 are simplified schematic representations of preferredcontrol circuit arrangements employed in connection with my shearapparatus.

Referring now to the drawings, and initially to FIG- URES 1-4 thereof,the reference numeral designates generally the material feedingapparatus, and the numeral 11 the shearing apparatus of my invention. Inaccordance with usual practice, the material feeding and shearingassemblies 10 and 11 are cooperating elements of the overall flyingshear apparatus combination, the arrangement being such that the rate offeeding of material, or line speed, at all times bears a direct relationto the period of the shear cycle.

In the illustrated embodiment of the invention the feeding apparatus 10comprises a pair of spaced upright stanchions 12 andy 13 in which arejournaled a pair of horizontally disposed pinch rolls or feed rolls 14and 15. In accordance with usual construction the upper feed roll 14 ismounted in vertically movable journal blocks, as at 16, and providedwith suitable adjusting means 17 and 18 for raising and lowering theroll 14 in relation to the lower roll 15. The purpose of this is, ofcourse, to provide for the accommodation in the feed rolls 14 and ofstrip material of various thicknesses.

As indicated in FIGURES 2 and 3, the feed rolls 14 and 15 are providedat one end with driving connections 19 and 20 respectively, by means ofwhich the feed rolls are associated with power means to be hereafterdescribed in considerable detail.

At the exit or outgoing side of the feed rolls 14 and 15 there isprovided a short run-out table comprising a plurality of rollers 21 forsupporting strip material, not shown, between the feeding and shearingapparatus.

Positioned at the rear of the feeding apparatus 10, in the direction ofmaterial feed, are a pair of widely spaced journal blocks 22 and 23which are rigidly secured to the machine base resting upon a suitablefoundation 24, and which journal and support an elongated shaft 25. And,in accordance with the teachings of the invention, there is supported onthe shaft 25 a carrier 26 which is preferably of relatively ruggedwelded construction. The carrier 26 is provided with a plurality ofspaced journal portions 27 and 28 which engage the shaft 25 in suchmanner as to permit rotation of the shaft and independent pivotalmovement of the carrier about the axis of the shaft. Securely mounted atthe upper edge of the carrier 26 is a shear blade 29 the upper edge ofwhich is positioned slightly below the pass line of material travelingthrough the feed rolls 14 and 15 and over the supporting rolls 21.

Forming an integral or assembled part of the carrier 26 is a journalassembly for rotatably supporting a pair of spaced threaded shafts, oneof which is indicated at 30 in FIGURE 4. In the preferred embodiment ofthe invention the threaded shafts 30 are supported in forwardly inclinedrelation to the general plane of the carrier 26, as is further indicatedin FIGURE 4. Engaging the lower ends of the shafts 30 is a reductiongear assembly, designated generally by the reference numeral 31, whichis powered by means of a suitable electric motor 32 mounted rigidly onthe carrier 26. And, as will hereafter be more fully explained, themotor 32 may be energized as desired to rotate the threaded shafts 30.

Engaging the shafts 30 are spaced internally threaded blocks 33 whichsupport a pivot pin or shaft 34. The shaft 34 pivotally engages a pairof spaced driving rods or links 35 which extend forwardly of the shearapparatus and are connected at their forward ends to the eccentric reach36 of a crankshaft 37. And in the preferred and illustrated embodimentof the invention the crankshaft 37 is journaled in the base portion ofthe feed roll supporting assembly. The crankshaft 37 is journaledgenerally below the feed rolls 14 and 15, and is provided with a drivingconnection which extends outwardly of the right-hand side of thestanchion 13, as indicated in FIG- URE 2.

As will be understood, upon rotation of the crank 37 the carrier 26 willbe caused to rock or pivot about the supporting shaft 25, the amplitudeof the rocking motion being proportionate to the distance of theconnecting shaft 34 from the supporting shaft 25 and hence capable ofadjustment by rotation of the threaded shafts 30.

Positioned in surrounding relation to the carrier 26, and guided forgenerally vertical sliding movement in the plane of the carrier, is arectangular frame member 38. The frame 38 is provided along its upwardlyextending side members 39 and 40 with guide channels 41 and 42 whichengage the upright side edges of the carrier 26 so that relativemovement between the carrier 26 and frame 38 may take place only in agenerally vertical direction, and only in the plane of the carrier. Inaccordance with the teachings of the invention the side members 39 and40 of the frame are provided with vertically elongated openings 43 neartheir lower end portions, through which openings the supporting shaft 25may pass without engaging the frame.

Also in accordance with the teachings of the invention the supportingshaft 25 is provided with a pair of eccentric portions 25 upon which arejournaled and supported spaced toggle assemblies, each comprised ofpivotally connected links 44 and 45, which engage the lower ends of theside members 39 and 40 and support the entire frame 38. The links 44 and45 are connected together by means of pivot pins 46. And when theselinks are locked in any position there is afforded a direct mechanicalconnection between the eccentric portions 25' of the supporting shaft 25and frame 38, the arrangement being such that upon rotation of the shaft25 the frame 38 is caused to move upward and downward, through areciprocatory cycle determined by the eccentricity of the portions 25.Any reciprocations of the frame 38 are, of course, relative to thecarrier 26, and for practical purposes, independent of any rockingmovement of the carrier, the frame 38 being carried along with thecarrier 26 during such rocking movement.

To connect the toggle assemblies 4446 with the frame 38 in the mannerdesired I have provided a shaft 47 which is journaled at each side ofthe frame 38, in the lower end portions of the side members 39 and 40thereof. Keyed or otherwise locked to the shaft 47, adjacent its ends,are the lower links 45 of the toggle assemblies 4446. The arrangement issuch that when the shaft 47 is locked against rotation with respect tothe frame 38 the toggle links 45 become, in effect, integral parts ofthe frame. Then, upon rotation of the shaft 25, the entire frame 38 iscaused to move through cycles of upward and downward reciprocatorymovement.

Secured to the frame 38 in the manner illustrated in FIGURE 4 are spacedfluid cylinders 48, which are preferably air-operated and of arelatively quick-acting type. These cylinders are positioned inspaced-apart relation but inwardly of the toggle assemblies 4446,substantially as shown in FIGURES 3 and 5. And in accordance with theteachings of the invention, the operating rods 49 of the cylinders 48extend in a forwardly direction and make connection with suitable rockerarms 50 which are rigidly secured to the shaft 47. Thus, uponenergization of the cylinders 48 in one direction or the other the shaft47 may be caused to rotate through a limited arc to change the relativeposition of the toggle links 44 and 45.

It will be noted, in regard to the toggle links 44 and 45, that the samehave an effective length equal to the distance between the centers ofeccentrics 25 and shaft 47. Thus, when the links 44 and 45 are alignedthe effective length of the assembly is longest, and the frame 38 issupported in its lowest relation with respect to the eccentrics 25. Thisarrangement is illustrated in FIG- URE 11, for example, of the drawings.

On the other hand, when the links 44 and 45 are in substantialmisalignment, as indicated in FIGURE 4, the effective length of thetoggle assemblies is substantially reduced, and for this reason theframe 38 is carried in relatively high relation to the eccentrics 25'and to the carrier 26.

Thus, in the assembled shear apparatus I have mounted on the upperportion of the frame 38 a shear blade 51 which is positioned so as to bein cooperative shearing relation with the lower shear blade 29 onlyduring reciprocatory movement of the frame 38 while supported in lowerrelation to the carrier 26; that is, only when the toggle mechanism44-46 is aligned, to have its maximum effective length. Whenever thetoggle mechanism is broken, by forward extension of the fluid cylinder48, as shown in FIGURE 4, the frame 38 rides sufficiently high duringits reciprocatory cycle of movement that the blades 51 and 29 do notmake engagement and the material passing through the shearing apparatusis not severed. It will thus be apparent that while the supporting shaft25 may be continuously rotated to effect a continuous upward anddownward reciprocation of the frame 38, actual shearing operations maybe selectively caused or prevented, as desired, by merely energizing thecylinder 48 to bring the toggle mechanism 44-46 into substantialalignment or to break such alignment, as may be the case. This simpleand highly practical arrangement for effecting cutting or mis-cutting isan important feature of the invention in that, aside from its inherentsimplicity, the operation of the shear is rendered more responsive todelicate control stimuli derived from a position remote from the shear.Heretofore complicated clutch and/or gear mechanisms have been employedto effect cutting and mis-cutting of the shearing apparatus. And it willbe readily apparent that such clutch mechanisms are sub ject to largeshock forces which result necessarily in higher construction andmaintenance costs.

In FIGURES 7-12 I have illustrated, in simplified manner, my novelshearing apparatus during several sequential stages of a completeshearing operation, the toggle mechanism being in aligned relation sothat shearing engagement is had between the shear blades 29 and 51.Thus, in FIGURE '7 the crank 36 and connecting rod 35 are carrying theframe 38 and carrier 26 through a rearward rocking movement whereby theshear blades 29 and 51 are carried along with the moving strip material.At the same time the shaft 25 and earns 25' are rotatedcounter-clockwise so as to cause frame 38 and shear blade 51 to movedownwardly with respect to the carrier 26 and shear blade 23. The crank36 and cams 25' are so oriented that the shear blade 51 is in its lowestposition when the carrier 26 is in an approximately vertical position asillustrated in FIGURE 8. Continued rotation of the crank 36 carries theframe 38 rearwardly beyond a vertical position, as in FIGURE 9, andduring this time the cams 25' rotate further in a counterclockwisedirection to raise the upper blade 51 out of shearing relation to permitthe continued travel of the material. During the return rocking movementof the frame 33 and carrier 26 the cams 25 are in a raised position, asindicated in FIGURES 10-42 so that the continuously moving material maypass freely through the shearing apparatus at this time.

As is clearly evident in FIGURE-S 7-12 the oscillatory or rocking motionof the blades 51 and 29, in the plane of movement of the Strip materialwill have an approximate harmonic or sine-wave relation to the velocityof the crank pin 36. Thus, if the crank shaft 37 were to have a uniformrotary movement, as has been common practice in the past, the velocityof movement of the blades 29 and 51 in the plane of strip travel wouldconstantly vary, approximately in accordance with the equation V=(wr)sine where w represents crank rotation in radians per unit of time, rrepresents the eccentricity of the crank 36 and the connecting rod 35.And

it may be readily understood that under such conditions was only anapproximate synchronization of the cutting blades with the stock to besevered.

In accordance with the teachings of the present invention I provide anovel mechanism for driving the crank 37 whereby substantialnon-uniformity of rotation is obtained and whereby such non-uniformityoperates to substantially compensate for the harmonic variations in the'shear blade velocity over a substantial portion of the shear cycle.Thus, in the illustrated embodiment of-the invention, I provide a drivemechanism 52, to be hereafter described more fully, having a drive shaft53 extending toward the shear apparatus in angularly disposed relation,the arrangement being such that the axes of the crank shaft 37 and driveshaft 53 intersect in angular relation. Then, to connect the shafts 37and 53 in driving relation I provide a large high power universal joint54 which,

in accordance with the preferred teachings of the invention, is a Hooketype universal joint, as distinguished from a constant velocity typejoint. The Hooke type universal joint is a common coupling used toconnect two shafts, the axes of which are not in line with each otherbut which merely intersect at a point. The joint comprises two forkedmembers mounted at the ends of the intersecting shafts and drivinglyconnect with each other by means of interconnected right angularlyrelated driving pins. A conventional form of the Hooke joint isillustrated at page 622, Machinerys Handbook, 13th edition, TheIndustrial Press, 1946.

As is well known, in a driving connection comprised of a Hooke typeuniversal joint there is non-uniformity of motion between the drivingelement and the driven element, in this instance members 53 and 37respectively, although, of course, both the driving and driven elementshave equal cyclic periods. At any instant the ratio of the speed of thedriven element to the speed of the driving element may be determined bythe following equation:

cos (a) co 1sin (a) cos (b) where o represents the rotational speed ofthe driven member, o represents the rotational speed of the drivingmember, (a) represents the acute angle made by the intersection of theaxes of the driving and driven members, and (b) represents the angulardisplacement of the driving yoke of the universal joint from the planedefined by the above mentioned axes. Thus, it will be apparent that thedriven member of the power train will rotate alternately at lower andhigher speeds than the driving member during each complete revolution ofthe latter. And it will further be apparent that relative non-uniformitybecomes more pronounced as the angle made by the axes of the driving anddriven element is increased.

In accordance with the above principles, I have determined that if thedriving and driven elements 53 and 37 are caused to intersect at anangle of in the order of 37 and are joined by a Hooke type universaljoint connection there will be produced in the driven member 37 anon-uniforrnity of motion which will substantially exactly compensatefor the normal harmonic variations of the driving component or vector ofthe crank pin 36 over a substantial portion of a rotational cycle.

Thus, in the graph of FIGURE 13 the curve designated by the letter Arepresents a normal harmonic or sine Thus, in prior apparatus of thissame gencurve which indicates the driving velocity component, or vector,of the crank pin 36, in terms of a percentage of the true velocity ofthe pin, over 180 of rotation of the crank 37. The curve designated bythe letter B represents the ratio as discussed above, for an angle ofintersection of 37. The product of the ordinates of curves A and B givesa very close approximation of the actual velocity of the shear blades 29and 51, in terms of a percentage of the true crank pin velocity, and inFIGURE 13 this product is represented by the curve C.

As is readily apparent upon inspection of curve C from 60 to 120 degressof crank rotation the curve is almost exactly horizontal, indicating analmost exactly uniform velocity of the shear blades 29 and 51 duringthis period. Mathematical computations, in fact, show that the variationin blade velocity during this period is less than one percent. Whereas,following the sine curve A" there is a variation of in excess ofthirteen percent over this same period, while there is a variation of inexcess of one percent over the period from 80 to 100 degrees of crankrotation.

In accordance with the teachings of my invention, therefore, there is asubstantial time period wherein the shearing operation may be completed.I make good advantage of this fact by providing for a substantial rakeor bias in the blades 29 and 51 (see FIGURE 5) so that the actualshearing operation progresses evenly from one side to the other of thematerial being sheared. The arrangement is such that stock ofsubstantial thickness, traveling at a high line speed, may beadequately'handled by shearing apparatus of moderate size, and theshearing equipment as a whole may be of lighter and more economicalconstruction than equivalent apparatus constructed in accordance withteachings heretofore advanced.

It should be understood, however, that the present invention is notlimited to mechanisms wherein the driving and driven elements 53 and 37intersect at an angle in the order of 37. Rather, the teachings areapplicable regardless of the magnitude of the angle, the specified rangebeing merely best suited for the illustrated application. An angularrange of from thirty to forty degrees is clearly contemplated in thepresent illustration.

It is of course contemplated, in the present invention that the shearblades 29 and 51 and frame 38 will be operated on the same cyclicperiods notwithstanding instantaneous velocity variations and the like.That is, during each rearward stroke of the rocking frame 38 and carrier26, the frame 38 and upper shear blade will move downwardly in shearingor mis-cut relation, depending upon the orientation of the togglelinkage 4446. Accordingly, I have provided a driving shaft 55, forming apart of the drive mechanism 52, which is geared for synchronous rotationwith the shaft 53, and which is connected in driving relation with thecarrier supporting shaft 25, the gearing being so synchronized that theframe 38 moves downwardly during rearward rocking movements thereof.

It will be readily understood, however, that in employing raked orbiased shearing knives a substantial movement of the frame is requiredto effect a complete shearing operation, as compared to apparatuswherein parallel shear knives are employed. In view of this, I havefound it desirable to speed up the operation of the shearing knivesduring the actual shearing operation so that the necessary substantialmovement of the knives may be effected, and the knives sufficientlyseparated, during the 50 to 60 degrees of rotation of the crank 37wherein substantially exact synchronization is had between the knivesand the moving stock.

To hasten the shearing action of the knives 29 and 51, as aboveoutlined, I have provided considerable offset between the shafts 55 and25, as shown in FIGURE 3, these shafts being oriented in parallelrelation in the illustration. Connecting the offset shafts 25 and 55 isan intermediate shaft, represented diagrammatically in FIG- URE 3 by thenumeral 56, there being a pair of uni versal joints 57 and 58 providingangular driving connection between the shafts 25 and 55 and theintermediate shaft 56. And in the preferred form of the invention theangle of intersection between the axis of the intermediate shaft 56 andthe respective axes of shafts 25 and 55 is in the order of 35.

In accordance with the teachings of the invention the universal joints57 and 58 are Hooke type joints. And as heretofore discussed, when suchjoints are angularly related a non-uniform driving relation is obtainedbetween the driving and driven members. Thus, it will be apparentthat anon-uniform driving relation is had, in the first instance, between thedrive shaft 55 and the intermediate shaft 56, and in the second instancebetween the intermediate shaft 56 and the carrier supporting shaft 25.Of course, the joints 57 and 58 may be arranged so that thenon-uniformity of driving relation in each case additively orsubstractively affects the other. That is, the joint 57 may be arrangedto amplify the non-uniformity produced in the joint 58, or to compensatetherefor, as may be desired. In the present instance, however, it isdesired to obtain a high acceleration of the shearing blades during theperiod of synchronous movement of the frame 38, so that the joint 57 isarranged to amplify the nonuniformity produced by the joint. This iseffected by positioning. the yokes carried by the shafts 55 and 25substantially at right angles, as illustrated in FIGURE 3. Thus,following the equation heretofore set forth relative to theinstantaneous rotational speed of the driving and driven elements of aHooke type universal joint, it may be shown that the shaft 25 willobtain a maximum rotational speed of close to percent of the rotationalspeed of the principal driving shaft 55, which rotates at a constantspeed. And by properly synchronizing the drive shafts 53 and 55 I mayeasily provide that this rapid rotational movement of the shaft 25 takesplace during the period of synchronous movement between the carrier 26and moving material, as will be readily appreciated.

For driving the shafts 25 and 37 and the feed rolls 14 and 15 in thedesired relation I have provided a novel transmission mechanism,represented generally by the numeral 52, which is powered by a suitablevariable speed electric motor 59, and which is operative to maintain theshafts 25 and 37 in exact synchronism and in predetermined speedrelation to the feed rolls 14 and 15.

Referring now to FIGURE 6 of the drawings, the transmission 52 isprovided with a casing or housing 60 from one end of which projects ashaft 61 adapted for connection to the electric motor 59. The shaft 61carries a worm 62 on its central portion, which drives a mating wormgear 63 at reduced speed to rotate a shaft 64 journaled in the housing66 in transversely disposed rela-tion to the power input shaft 61. Atone end the shaft 64 carries a pinion gear 65 which meshes with anddrives a similar gear 66 journaled in the housing 60 below the gear 65.Keyed or otherwise secured to the gear 66 is the drive shaft 55 whichextends outwardly of the housing 60 for connection with the carriersupporting shaft 25 in a manner heretofore described. The arrangement issuch, as will be apparent, that a positive direct gear drive is affordedbetween the motor 59 and the carrier supporting shaft 25, which is inaccordance with the preferred practice in flying shear construction.

Also keyed or otherwise secured to the shaft 55 is a bevel gear 67 whichmeshes with a similar bevel gear 68 carried by the drive shaft 53. Theshaft 53 is disposed in angular relation to the housing 60, as will beobserved, so that. there may be an angular driving connection betweenthe shaft 53 and crank 37 as has been discussed previously. And in theillustrated apparatus the bevel gears 67 and 68 are of a one-to-oneratio so as to have equal cyclic periods.

Shaft 53, and hence the crank 37, will also have a direct drivingconnection with the motor 59 as will be readily observed.

At the forward end of the shaft 61, which is connected directly to themotor 59, there is provided a pinion gear 69 which meshes with anddrives a. gear 70, forming a part of a differential drive mechanismdesignated generally by the numeral 71. A bevel gear 72 forms anintegral part of, or is rigidly secured to the pinion 70 so as to rotatetherewith at all times.

Positioned opposite the bevel gear 72, in spaced relation thereto but inaxial alignment, is a second bevel gear 73 which is a substantialduplicate of the bevel gear 72. And the bevel gear 73 is likewiserigidly secured to or forms an integral part of a pinion gear 74. I

Between the bevelgears 72 and 73, and meshing with the same, are aplurality of small bevel gears 75 which are journaled and supported by acommon spider-like member 76 positioned in axial alignment with thelarger bevel gears 72 and 73. This structure represents a conventionaldifferential drive mechanism. And, as will be understood, thearrangement is such that the spider-like differential element 76 rotatesat a speed equalling onehalf the sum of the rotational speeds of thebevel gears 72 and 73. The first mentioned bevel gear 72, of course, isat all times driven at a speed proportionate to the speed of the motor59. But, by regulation of the speed of rotation of the pinion 74 andbevel 73 it is possible to vary the speed of rotation of thedifferential element 76 independently of the motor 59. This is describedmore fully below.

Keyed to the spider-like differential element 76 is a shaft 77 which isjournaled in the housing 60 and which carries a bevel gear 78intermediate its ends. The bevel gear 78 drives a second bevel gear 79carried by a drive shaft 80 extending from the housing 60. The shaft 80carries a pinion 81 intermediate its ends which drives a second similarpinion, not shown, carried by a second shaft 82 located directly belowthe shaft 80 and disposed in parallel relation therewith. The shafts 80and 82 are connected through couplings 19 and 20 with the feed rolls 14and 15. Thus, it will be observed that while the frame and carrierassembly and shear blades are driven by direct drive from the motor 59,the feed rolls 14 and 15 are driven from the motor 59 through thevariable differential mechanism 71, permitting variation in the cyclicperiod of the shear apparatus in relation to the line speed of thematerial fed, in accordance with usual flying shear construction.

In order to vary the speed of rotation of the bevel gear 73 of thedifferential mechanism, and thereby to regulate the rotation of the feedrolls in relation to the shear apparatus, I have provided a pinion 83which meshes with the pinion 74 and which may be driven in variablespeed relation to the motor 59. As illustrated in FIGURE 6, the pinion83 is carried by a shaft 84 journaled in the housing 60 and driven bymeans of mating bevel gears 85 and 86. To drive the pinion 86 I providea conventional variable speed positive drive device '87, which may be acommercial device known in the trade as a P.I.V., the initials P.I.V.representing the words positive-infinitely-variable. In accordance withthe teachings of the invention the pinion 86 is connected to the outputshaft 88 of the P.I.V. device 87.

Secured to the input shaft 89 of the P.I.V. device 87 is a small bevelgear 90 having driving engagement with a large diameter pinion 91carried at the end of shaft 77. The same shaft which drives the feedrolls 14 and 15, therefore, drives the input shaft of the P.I.V. unit87, and this is an important aspect of the present invention as willpresently appear.

It is contemplated by the present invention that the P.I.V. unit 87 willbe a standard commercial product, having a variable input-to-outputratio of from in the order of ten-to-five to ten-to-twenty-five, or atotal variation of about five-to-one. And, of course, the unit 87 isprovided with means 87 (see FIGURE 15) for adjusting the input-to-outputratio as desired.

By following the gear train beginning with the bevel gear 72 andincluding the shaft 77, P.I.V. 87 and pinions 83 and 74, it will beobserved that the rotation of the gear 74 will be opposite in rotationto that of the gear 78. That is, observing from the end of the housingfrom which the power input shaft 61 projects, the bevel gear 72 isrotating in a clockwise direction, while the bevel gear 73 is in acounter-clockwise direction. And the gear ratios have been selected sothat the bevel gear 73 at all times rotates at a slower speed than doesbevel gear 72. Thus, upon the application of power to the bevel gear 72the shaft 77 will be caused to rotate slowly in a clockwise direction ata speed equal to one-half the difference between the speeds of rotationof the bevel gears 72 and 73. And by adjusting the P.I.V. unit 87 tovary the speed of rotation of bevel gear 73 in relation to the speed ofrotation of the shaft 77 the speed of the latter may be varied inrelation to the speed of the driving motor 59, as desired. For example,if the P.I.V. unit 87 is adjusted so as to have an increased outputspeed in relation to its input speed, the bevel gear 73 will tend torotate at an increased speed, causing a more pronounced substractiveeffect upon the differential mechanism 72 and thereby slowing down theshaft 77 in relation to the input speed of the motor 59.

In normal operation of the shearing and drive mechanism described hereinit is generally desirable to maintain the rate of travel of the materialat a constant speed at all times. Therefore, in order to adjust theshearing mechanism so as to sever shorter lengths, for example,

it is necessary to increase the frequency at which the shear frame andknives operate. To accomplish this the motor 59 is speeded up as will bereadily understood. However, as the speed of the motor 59 increases thefeed rolls 14 and 15 also tend to rotate at a greater speed. So it isthen necessary to adjust the P.I.V. mechanism to slow down the speed ofthe shaft 77 in relation to the speed of the motor 59. The desired endresult being that the shaft 77 rotates at a constant speed at all timesto maintain a constant prevailing line speed.

In reference, again, to FIGURE 6 it will be noted that the input shaft89 of the P.I.V. unit is driven directly from the shaft 77, so that inthe normal operation of the shear equipment the P.l.V. input ismaintained constant notwithstanding side variations in the cyclic periodof the shear knives. This is an advantageous feature of the presentinvention in that standard P.I.V. drive units of the type hereincontemplated operate most efliciently at a predetermined constant inputspeed. And the apparatus may be readily designed to maintain an optimuminput speed for the P.I.V. unit employed.

As a general rule, adjustment of the speed of the drive motor 59 toeffect an increase or decrease in the number of shearing cycles per unitof time is always accompanied by an appropriate adjustment of the P.I.V.unit 87 to the end of maintaining the rotation of the feed rolls 14 and15 constant. Accordingly, it may be desirable to mechanicallyinterconnect the motor and P.I.V. adjustmerits so that a singlemanipulative operation will produce the desired overall adjustment. Suchan arrangement is illustrated in FIGURE 14 wherein the adjusting wheel87 for the P.I.V. unit 87 is mechanically interconnected with aregulating rheostat, or variable resistor, 90, which forms a part of thepower circuit for the motor 59. The mechanical interconnection, which isschematically represented at 91, may include suitable gear reductionmeans, not shown, so that when the wheel 87 is adjusted the motor speedis altered as necessary to maintain the line spas-37o 11 speed of thematerial constant. It will be understood, of course, that it isgenerally not necessary to maintain the line speed of the materialexactly uniform at all times so that slight non-linearity in the motorand P.I.V. adjustments is of no particular consequence.

Whenever the cyclic period of the shear apparatus is increased ordecreased to effect longer or shorter cuts the speed of movement of theshear blades will be changed accordingly, since the same is a functionof the speed of rotation of the crank 37. Thus, for example, where thecyclic period of the shear is decreased, to produce shorter cuts, it isnecessary to reduce the amplitude of the rocking movement of the shearframe 38 so that the actual velocity of the blades remains synchronizedwith the material. In accordance with the teachings of the presentinvention this is accomplished by rotating the threaded shaft 36 toraise the point at which the connecting link 35 engages the carrier 26.The crank pin 36, of course, has a fixed amplitude of movement so thatas the link 35 is raised or moved away from the pivotal axis of thecarrier 26 the same will have a movement of lesser amplitude, causingthe blades 29 and 51 to move at a reduced speed in the direction ofstrip movement. Thus, it will be clear that for each setting of theP.I.V. 87 there is a corresponding setting for the connecting link 35 atwhich the velocity of the shear knives moves in synchronism with thestrip material during shearing operations.

In the illustrated embodiment of the invention the shaft 30 is rotatedby motor 32, controlled from a remote station, not shown. And it iscontemplated that suitable selsyn or limit switch controls may beemployed to automatically correlate the operation of motor 32 withadjustments effected at the P.I.V. unit 87.

In its preferred form, the apparatus of my invention is adapted for atwo-to-one adjustment of the shear cycle in relation to the line speedof the material, so that the maximum length of material which may besheared in a single shear cycle is at least twice the length of theminimum section which may be sheared. Where longer sections of materialare desired I provide means, including the toggle mechanism 4446, forrendering the shear apparatus ineffective during certain of its cycles.For example, in order to cut sections equalling three times the lengthof the minimum section the shear apparatus is adjusted to have ashearing cycle which would produce a cut section equal to one andone-half times the minimum section. But the shearing apparatus isarranged to be ineffective, or to miscut, during alternate cycles, sothat the actual cut sections are equal to three times the minimumsection. And it is understood, of course, that any number of mis-cutcycles may be provided so that it is possible to obtain an actual cutsection which is many times the length of the minimum section, theapparatus being infinitely adjustable over its entire range as will bereadily apparent.

To produce mis-cut cycles in the manner desired I prefer to employ asimple counter circuit which is operative to count a predeterminednumber of mis-cut cycles, and thereupon to condition the shearingapparatus for an actual shearing operation.

Thus, in FIGURE 14 there is shown a switch 91 which is positionedadjacent one of the eccentrics 25 of the supporting shaft 25 and whichis arranged to be actuated once during every revolution of the shaft 25.The switch 91 is connected through conductors 92 and 93 to counter panel94, which may be of conventional design, for registering the number oftimes the switch 91 closes, or the number of cycles of operation of theshearing apparatus. In accordance with the teachings of the inventionthe counter 94 is provided with an adjustment 95 which may be set forany predetermined number of cycles. And upon such predetermined numberof cycles being reached a circuit is completed by the counter 94 to asolenoid operated valve 96, energizing the same, and directing fluidunder pressure to the forward or rod end of the cylinder 48. At thistime the toggle mechanism 44-46 is straightened, and during the nextsucceeding downward stroke of the frame 38 blades 29 and 51 moving intoshearing relation, severing the desired length of material. The counter94, of course, resets at this time and again counts a predeterminednumber of mis-cut cycles before energizing valve 96. While valve 96 isin a deenergized condition fluid is directed to the head end of cylinder58 to maintain the toggle 4446 in broken or mis-cut condition.

The counter 94 is preferably in the form of a common electronic digitalcounter or computer which is adapted to receive and record periodicalelectric impulses transmitted thereto upon closure of switch 91, and toenergize an actuating circuit for the valve 96 upon the registration ofa predetermined adjustable number of such impulses. 'In general suchcounters comprise a plurality of electrically interconnected electronicvalves which are caused to conduct in predetermined sequential relationin response to the reception of periodical signal pulses, and when thepreset. number of pulses is indicated by the conduction of apredetermined combination of electronic valves an output control circuitis energized and all of the electronic valves are extinguished,preparing or resetting the counter for a new control series.

As shown in FIGURE 15, the counting switch 91 is positioned so as to beactuated during upward movement of the shear frame 33 so thatsubstantial time is provided for the toggle mechanism 44-46 tostraighten prior to the following downward stroke, wherein an actualshearingoperation is effected. It should now be apparent that I havecarried out the objects initially set forth. The apparatus of myinvention incorporates a number of novel and advantageous features whichjointly and separately provide for substantial improvement in the flyingshear system.

One of the most important features of my invention resides in thecombination with a crank operated shear device of a drive mechanismincluding a universal joint set at a fixed angularity and arranged withrespect to the driving crank for the shear so that harmonic variationsin the movement of the crank are substantially eliminated over a largeportion of the shearing cycle. The arrangeent is such that a substantialperiod of time is afforded in which the actual shearing operation may becompleted so that the shear blades may have considerable rake or biasand the shearing force may be applied slowly and evenly. My improvementin this regard permits a reduction of large magnitude in the actualshearing force required and in shock forces which are more or lessinherent in apparatus of this nature. In turn, the shear frame andallied apparatus may be of relatively lightweight construction,simplifying and lightening the mechanism required to carry the shearapparatus through its required oscillatory movements.

It should be noted, however, with reference to this aspect of myinvention, that a universal joint set at a fixed angularity is not thesole mechanism which may be successfully employed to obtain suchsubstantial uniformity of shear blade motion. Thus, such mechanism aselliptical gear trains may be utilized, to the end that thenon-uniformity of transmission caused by the mechanism usedsubstantially compensates for the harmonic variations in shear motionproduced by the crank or eccentric drive.

Another novel feature of my invention is the simplified and inherentlyrugged arrangement for adjusting the point at which the driving links 35connect the shear frame carrier 26. Thus, I have employed threadedshafts which extend generally radially from the point of support for thecarrier 26 so that upon rotation of the shafts the connecting links 35are moved toward or away from the point of support. And when the drivingcrank 36 is speeded up, for example, it is merely necessary to raise thedriving links 35 a proportionate amount so that the shear knives remainin synchronism with the moving strip material. In addition. it will beobserved that as the cyclic period of the shear apparatus is reduced,requiring greater acceleration of the shear components, the point ofconnection between the carrier 26 and links 35 is raised so thatincreased driving leverage is obtained.

in combination with means to render the movement of the shear knivessynchronous with the moving strip material over a substantial distance Ihave further provided a drive mechanism for effecting shearing movementof the knives which includes transmission means for producing anon-uniform shearing motion, to the end that the shearing operation iscarried out with substantial rapidity even though the knives have agreater amplitude of movement than has been common heretofore. In thepresent illustration 1 have employed a pair of universal joints, set ata constant angularity, which produce an additive non-uniformtransmission effect during downward movement of the shear frame 35whereby the same is accelerated to a higher velocity during that portionof the shear cycle during which shearing actually takes place. Hereagain, however, the invention is not restricted to the use of universaljoints for this purpose, but contemplates the use of any equivalentmechanisms such as elliptical gears, for example. mechanisms, however,as the same are generally more simple and efficient, and, if properlyconstructed, are more rugged and therefore more suitable for the purposeintended.

It will be noted, further, that while the shear frame 38 is acceleratedin its vertical or shearing movements, the frame 38 and carrier 26 aredecelerated in rocking movement. The arrangement is such that theincreased power provided for acceleration in one case is partiallyprovided by the release of energy from deceleration in the other case.And, optionally, a suitable fly-wheel 97 (see FIG- URE 3) may beprovided to reduce load variations on the drive motor 59.

Another advantageous feature of my invention is my novel transmissionassembly, including a P.I.V. umt, wherein the P.I.V. unit and adifferential drive assembly are utilized to drive uniformly rotatingfeed rolls, while a direct drive connection is aiforded between theconstantly accelerating and decelerating shear assembly and the maindrive motor 59. Of course this type of drive assembly is not broadlynew, but the apparatus of the present invention has the outstandingadvantage of having a constant speed input for the P.I.V. unit, whichhas not heretofore been accomplished where the P.I.V. unit has beenemployed in the feed roll drive with a direct drive for the shearapparatus. In accordance with the teachings of my invention the P.I.V.input has direct connection with the feed rolls 14 and 15, which arepreferably driven at a substantially constant speed. And the driveratios are so chosen as to cause the P.I.V. unit to have a highefliciency output under all conditions of operation.

My transmission assembly is further advantageous with respect to itsgeneral compactness and unitary construction. All drive shafts extendfrom a single compact housing, with simple external coupling connectionsfor the drive motor and P.I.V. unit which are preferably of standardcommercial design and construction.

A further advantageous feature of my invention resides in the simplifiedtoggle mechanism 44-46 for effecting cuts or mis-cuts as desired.Heretofore it has been common to employ clutch mechanisms and the likewhich are necessarily subject to severe shock forces and thereforesubject to high construction and maintenance costs. My invention, on theother hand, contemplates a continuously oscillating shear frame member,the center of oscillation of which may be changed by breaking oraligning a simple toggle mechanism which connects the shear frame withthe drive eccentrics therefor. It Will be noted,

I prefer universal joints over these other 7 also, that I may readilyemploy, with my improved miscut mechanism, a simplified controlarrangement comprising a counter device and a fluid valve responsivethereto, whereby a predetermined number of mis-cuts may be effectedbetween each cut. By this arrangement the useful range of my apparatusmay be extended to all practical limits, while the mechanical adjustmentmeans employed afford adjustment over merely a two-to-one range, from aminimum length to at least twice such minimum length.

it should be understood, however, that the apparatus herein illustratedand described in detail is intended to be illustrative only andreference Should therefore be had to the following appended claims indetermining the full scope of the invention.

I claim: I

1. In a drive system for a mechanical assembly having a work mechanismand a stock feed mechanism; the combination of a variable speed drivemotor for said work mechanism, a differential gear assembly having apair of independently rotatable gears and a differential element engagedby each of said independently rotatable gears and rotatable at a speedwhich is a function of the rotational speeds of said independentlyrotatable gears, drive means connecting said motor and one of saidindependently rotatable gears, a drive shaft for said feed mechanisms,said drive shaft connecting with said differential element, and means todrive the other of said independently rotatable gears comprising apositive-infinitelyvariable drive device having a driving connectionwith said drive shaft.

2. In a drive system having a pair of output shafts and a variable speeddriving motor, means constituting a direct drive connection between afirst of said output shafts and said motor, a differential gearmechanism having a pair of independently rotatable gears and adifferential element operated thereby, means constituting a direct driveconnection between the second of said output shafts and saiddifferential element, means to rotate one of said independentlyrotatable gears constituting a direct drive from said motor, and meansto rotate the other of said independently rotatable gears comprisingsaid differential element and a positive-infinitely-variable drivedevice.

3. Apparatus according to claim 2 further characterized by said drivedevice having an adjusting element, and further including a speedadjusting control element for said driving motor, and meansinterconnecting said adjusting element and control for correlatingadjustments of said motor and drive device.

4. In a drive system for driving and controlling the relative speedbetween a feed mechanism of normally constant speed and a work mechanismwhose speed is adjustable in relation to the speed of the feedmechanism; the combination of an adjustable speed motor, a shaft fordriving said work mechanism coupled with said motor whereby said workmechanism operates in accordance with the speed of the motor, adifferential gear assembly having one drive gear connected to and drivensynchronously with said shaft, a positive infinitely variable speeddrive device having an input shaft connected to and synchronously drivenwith respect to the first mentioned shaft, said variable speed drivedevice having an output shaft connected to the other drive gear of saiddifferential gear assembly, said differential gear assembly having a'rotatable element engaging said drive gears and rotatable at a speedwhich is a function of the relative rotational speeds of said drivegears, and means coupled with said element for driving said feedmechanism.

5. Apparatus according to claim 4 further characterized in that saiddrive system is a unitary assembly in which said shaft and said couplingmeans is journaled in a common case, said case also journalling a shaftadapted to be coupled directly with said motor and also housing saiddifferential gear assembly, said positive infinitely variable speeddrive device being housed prin- ,15" cipally in a separate housingcontiguous to said casing and having input and output shafts extendinginto said casing, the mechanical connections between the first mentionedshaft and said input shaft and between said output shaft and the saidother gear of said difierential gear assembly being housed entirelywithin said casing.

6. In a drive system for driving and controlling the relative speedbetween a feed mechanism of normally constant speed and a Work mechanismwhose speed is adjustable in relation to the speed of the workmechanism; the combination of an adjustable. speed motor, a shaft fordriving said work mechanism coupled with said motor whereby said workmechanism operates in accordance with the speed of the motor, adifferential gear assembly having one drive gear connected to and drivensynchronously with said shaft, a positive infinitely variable speeddrive device having an output shaft for driving the other drive gear ofsaid differential gear assembly,

said diiierential gear assembly having a rotatable element engaging saiddrive gears and rotatable at a speed which is a function of the relativerotational speeds of said drive gears, an input shaft for said positiveinfinitely variable speed drive device, means to apply rotative power tosaid input shaft, and means coupled with said element for driving saidfeed mechanism.

References Cited in the file of this patent UNITED STATES PATENTS624,186 Daly May 2, 1899 1,958,538 Haliden May 15, 1934 2,221,186 GroschNov. 12, 1940 2,261,007 Talbot Oct. 28, 1941 2,305,128 Andresen et a1Dec. 15, 1942 2,476,466 Thomas July 19, 1949 2,495,988 Sheppard Jan. 31,1950

